docs: def graftm_package_is_protein(graftm_package):
          '''Return true if this package is an Amino Acid alignment package, otherwise
          False i.e. it is a nucleotide package. In general it is best to use
          'is_protein_package' instead.
  
          '''
          found = None
          with open(graftm_package.alignment_hmm_path()) as f:
              r = f.read().split("\n")
          for line in r:
              if line=='ALPH  DNA':
                  found = False
                  break
              elif line=='ALPH  amino':
                  found = True
                  break
          if found is None:
              raise Exception("Unable to determine whether the HMM was amino acid or dna")
          return found